:relfileprefix: ../../../
[#boost-urls-url_view_base-has_query]

= xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/url_view_base.adoc[pass:[url_view_base]]::has_query


Return true if a query is present


== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/url_view_base.hpp#L1852[boost/url/url_view_base.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
bool
has_query() const noexcept;
----

== Description


This function returns true if this
contains a query. An empty query is
distinct from having no query.

=== Example
[,cpp]
----
assert( url_view( "/sql?id=42&col=name&page-size=20" ).has_query() );
----

=== Complexity

Constant.

=== Exception Safety

Throws nothing.

=== BNF
[,cpp]
----
query           = *( pchar / "/" / "?" )

query-param     = key [ "=" value ]
query-params    = [ query-param ] *( "&" query-param )
----

=== Specification

* link:https://datatracker.ietf.org/doc/html/rfc3986#section-3.4
            >3.4.  Query (rfc3986)</a>
        @li <a href=[:&sol;&sol;en.wikipedia.org&sol;wiki&sol;Query_string"            &gt;Query string (Wikipedia)]








== See Also


xref:boost/urls/url_view_base/encoded_params.adoc[encoded_params]
,
xref:boost/urls/url_view_base/encoded_query.adoc[encoded_query]
,
xref:boost/urls/url_view_base/params-05.adoc[params]
,
xref:boost/urls/url_view_base/query.adoc[query]
.